458 FXUS64 KLZK 091743 AAA AFDLZK Area Forecast Discussion...UPDATED National Weather Service Little Rock AR 1243 PM CDT Tue Oct 9 2018 .AVIATION... For the 18z TAFs, mainly MVFR conditions will continue through the period as thunderstorms move into the state from the west. Expect several rounds of thunderstorms to move through the state between this afternoon and Wednesday morning/early afternoon. There should be short breaks in the heavy rain between rounds of thunderstorms, but for the most part conditions should not fully improve until a strong cold front passes through the area on Wednesday late morning/early afternoon. In addition to heavy rain and low clouds, gusty winds around 20-25kts are possible, especially across northern Arkansas. && .PREV DISCUSSION...(ISSUED 615 AM CDT Tue Oct 9 2018) AVIATION... Conditions will gradually deteriorate through the day, with MVFR conditions prevailing in the north by this afternoon, and in the remainder of the area from late afternoon into the overnight hours. Showers and thunderstorms will develop and become prevalent at all sites by this evening, with conditions lower in heavier precipitation. PREV DISCUSSION...(ISSUED 337 AM CDT Tue Oct 9 2018) SHORT TERM...Today Through Wednesday Night Surface analysis indicates a stationary frontal boundary from the panhandles region of Texas and Oklahoma, extending into northern Missouri, with another developing front over west Texas into northern Mexico. In the warm sector, there were several weaker boundaries over west Texas into Northeast Oklahoma, with showers and thunderstorms developing along and ahead of them. In the upper levels, ridging which has been the big block to any surface systems the last couple of weeks was shifting eastward off the Atlantic coast. Even with the ridge shifting eastward, the longwave pattern will remain amplified, as troughing digs down into the southern Rockies. As the trough ejects northeastward today and tonight, it will push the developing front across the Southern Plains and into the Mid South Region. There will be several waves of showers and thunderstorms over the next 24 hours. The precipitation in eastern Oklahoma will be shifting into Arkansas later this morning. A surface wave will move up in the mean flow ahead of the approaching front, with more showers and thunderstorms later today, and precipitation becoming fairly widespread. The third round will be with the main front tonight and early Wednesday. The front will be moving across Arkansas during the day Wednesday, and, based on the latest model data, it will likely be clearing the state during the afternoon hours, with rainfall coming to an end as cooler and drier air moves in behind it. Temperatures will remain above average ahead of the front, but will likely level off as the front passes, and could fall a little bit behind it. More importantly, the long term looks to be much more pleasant. As far as specific hazards... There will be a risk of strong thunderstorms this afternoon and tonight, and briefly on Wednesday ahead of the front. Given the fairly dynamic nature of the system, the primary threat with any strong storms will be gusty winds. The highest threat of strong storms will be over western Arkansas, ahead of the front this afternoon and tonight. Low level shear profiles are even sufficient enough for a brief tornado threat. However, with expected cloud cover ahead of the front, there will likely not be much opportunity for large-scale surface based destabilization in Arkansas, which doesn't give me much confidence in the overall threat. Another issue to contend with will be heavy rainfall. Deep stream of moisture from the Gulf and Pacific will push precipitable waters near two inches, and as I said before there will be several waves of rainfall. The most likely scenario will be a good one to two inches of rainfall over the western half of Arkansas, with locally heavier amounts. While heavy rainfall could create localized flooding issues, the progressive nature of the overall system should preclude a prolonged or widespread threat. LONG TERM...Thursday Through Monday Night More persistent Fall temperatures will be seen throughout the long term period...with just a brief warm up forecast over the weekend... A cold front will be well SE of the state at the start of the long term period...with NRLY SFC flow bringing in much cooler and drier air to the region. Temps will be below normal for Thu and Fri...with chances for rainfall remaining low. The coldest temps this week will occur on Fri morning...with SFC high pressure settling just north of AR over MO. Temps will range from the upper 30s to upper 40s for most areas Fri morning. High pressure will shift east for Sat into Sun...with SRLY SFC flow gradually returning to the region. This will bring warmer temps and increasing moisture to the CWA. SFC low pressure will develop the west of AR Sat into Sat night as a deepening upper shortwave trough exits the Rockies. This SFC low will lift NE over portions of the state...mainly over the NWRN sections on Sun...with a new cold front surging SE through the state Sun night into Mon. Expect increasing chances for SHRA/TSRA as this storm system traverses the area. There does remain some uncertainty right now regarding the overall strength of this SFC low and upper dynamics. However...it does look fairly probable that much of AR looks to be in the warm sector of this storm system during the daylight hrs Sun. This may result in some chances for strong to SVR TSRA on Sun. The exact timing and expected hazards are a bit uncertain this far out however. By Mon and Mon night...expect another surge of colder...drier air to move into the region. This will result in decreasing POPs and more below normal temps to wrap up the forecast. FIRE WEATHER... No significant fire weather issues are expected through the next seven days. Minimum humidity will remain above 50 percent, with 20 foot winds of 10 MPH or less. The highest rain chances will be this afternoon, tonight, and early Wednesday as a cold front moves across the state. && .LZK Watches/Warnings/Advisories...NONE. && $$ Aviation...CROSS